[mlir][Linalg] Add transform to convert linalg.copy into memref.copy (#132422)
Targeted rewrite of a linalg.copy on memrefs to a memref.copy.
This is useful when bufferizing copies to a linalg.copy, applying some
transformations, and then rewriting the copy into a memref.copy.
If the element types of the source and destination differ, or if the
source is a scalar, the transform produces a silenceable failure.